Hannaford cc data thieves planted malware on 300 servers

The data breach at Hannaford, the US grocery chain, which enabled the theft of info on more than 4.2 million credit card accounts was caused by a sophisticated piece of malware that attackers installed in all the company's retail outlets.

Installed on more than 300 servers in at least six states, the malware was able to intercept credit card data while customers paid for purchases using plastic and transmit the information overseas, The Boston Globe reports. The rogue software was installed on servers in close to 300 different locations, though the company isn't saying how it got there.

The malware lifted "track 2" data stored on the magnetic strip of customers' cards as customers used them at point-of-sale machines. The data includes the card number and expiration date, but not the customer's name. The malware stored records of the purchases in batches and periodically transmitted them to an unidentified offshore internet service provider, according to the company.

Security experts have been eager to figure out how thieves siphoned the data out of Hannaford Brothers Cos. network because the company is believed to have been following payment card industry (PCI) rules. If the east coast chain's systems were vulnerable, plenty of other retailers may be open to the same attack, the experts have warned. By contrast, TJX Cos, which in 2006 was robbed of credit data belonging to more than 100 million of its customers, flouted several important restrictions.